On January 12, 2022, after five years of scientific and technological research, ZGDY Power Materials Technology Corporation R&D personnel developed a new type of aluminum single wire – gradient microstructure semi-hard aluminum single wire. On the premise of not reducing the electrical conductivity of semi-hard aluminum, the tensile strength of semi-hard aluminum single wire is increased by more than 50%, breaking through the technical "bottleneck" that the strength and conductivity of aluminum wire are mutually constrained.
The improvement of wire strength helps to improve the technical economy of the transmission line, saves the steel consumption of the tower, and reduces the carbon emission of the steelmaking capacity; the improvement of the electrical conductivity helps to further reduce the power loss of the line and reduce the carbon emission of coal-fired power generation. An increase in the strength of aluminum conductors for overhead wires is usually accompanied by a decrease in electrical conductivity.
Gradient microstructured metals have the advantages of high strength and good toughness, and have always been a hot spot in the scientific research of metal materials at home and abroad. Relying on the National Natural Science Foundation of China project "Instability mechanism of multi-level microstructure aluminum wire under high temperature and high dependent variable coupling conditions", ZGDY carried out mechanism research, and introduced gradient microstructure into semi-hard aluminum single wire for the first time. The high and low temperature pre-torsion test platform has successfully developed a multi-level gradient microstructure semi-hard aluminum single wire. The semi-hard aluminum single wire with multi-level gradient microstructure achieves the synergistic improvement of strength and conductivity. On the premise that the conductivity of the semi-hard aluminum single wire reaches 62.5% of the conductivity of the International Annealed Copper Standard (IACS), it is the first breakthrough at home and abroad. The tensile strength of semi-duralumin single wire reached 110 MPa and reached 160 MPa.
It is understood that, taking the 500 kV angle steel straight tower with a span of 500 meters as a reference, on the premise that other design parameters of the transmission line remain unchanged, if the strength of the aluminum wire is increased by 10%, the sag can be reduced by 9%, and the height of the tower can be reduced. 1.3 meters, each base tower saves 6.5 tons of steel. It is estimated that in the power industry, the new aluminum single wire can save 6.5 million tons of steel for the tower and 11.05 million tons of carbon dioxide emissions from steelmaking energy consumption every year after full application.